Microcirculation reconstruction bone implant capable of generating internal stress

Abstract

A microcirculation reconstruction bone implant capable of generating internal stress comprises a support shell and a support inner core. The support inner core is sleeved with the support shell, and the support shell and the support inner core form a matched structure. The stent shell is located between the bone tissue and the stent inner core, and the stent shell generates elastic deformation to generate internal stress and applies the internal stress to the surrounding bone tissue when the stent is implanted and loaded; a microcirculation reconstruction passage is also loaded on the stent inner core; by adopting a mode that the stent inner core is matched with the stent shell, the stent inner core is matched with the stent shell to form an elastic effect, so that internal stress can be continuously applied to bone tissues in postoperative application to promote bone growth and integration; and a complex stress environment can be adaptively adjusted, so that the stress compatibility between the implant and a bone tissue is ensured, new intraosseous circulation is established, and the postoperative healing effect after the implant is applied is promoted.

Description

Technical Field

[0001] The present invention relates to medical devices, and more particularly to an implant for bone reconstruction, in particular to a microcirculation reconstruction bone implant capable of generating internal stress. Background Art

[0002] Femoral head necrosis, also known as avascular necrosis of the femoral head (ONFH), is a common and intractable disease in orthopedics. It is caused by a variety of factors, resulting in localized poor blood flow to the femoral head, leading to further bone cell ischemia and necrosis, trabecular fracture, and femoral head collapse. Without effective treatment, approximately 80% of patients will experience femoral head collapse within 1-4 years, leading to subsequent joint dysfunction and ultimately requiring total joint replacement surgery. The high cost of total joint replacement places a significant financial burden on patients and society. Furthermore, due to the limited lifespan of artificial joints, young and middle-aged patients often face joint loosening after replacement. Revision surgery is difficult and risky, further increasing the financial burden and significantly reducing patients' quality of life. Recent studies have shown that the incidence of femoral head necrosis has been increasing annually, and the age of onset is trending younger. Therefore, early treatment of femoral head necrosis to help patients preserve their natural joints has attracted considerable attention. Currently, there is no unified principle or consensus for the treatment of early-stage ONFH, and treatment is often determined by physicians based on their knowledge, skills, and experience. Clinical treatments for early-stage ONFH can be categorized as nonsurgical or surgical. While nonsurgical treatments can alleviate symptoms, there is insufficient evidence to demonstrate that they can prevent femoral head collapse, preserve joint function, delay joint replacement, or cure ONFH. Among the various hip-preserving surgical approaches for early-stage ONFH, core decompression combined with various bone repair biomaterials and / or structural bone support can effectively eliminate dead bone, reduce intraosseous pressure, open sclerotic areas, improve femoral circulation, thereby enhancing bone formation, promoting neovascularization, reducing the risk of proximal femoral fractures, and improving the treatment outcome of ONFH. Therefore, early lesion removal, implantation of support defects, and promotion of bone regeneration are currently hot topics in research and clinical treatment.

[0003] Existing support implants are usually threaded into a femoral hole in the femoral head. The implant is inserted by applying force to the coronal end of the implant in the insertion direction. The implant can only replace the necrotic tissue inside the femur and achieve internal support. It cannot provide internal microcirculation reconstruction and promote bone tissue growth and integration with the implant as soon as possible. For example, the metal tantalum rods used in conventional femoral head necrosis implants can only play a mechanical support role and cannot stop the pathological process of femoral head necrosis. The bone integration ability is not strong and cannot solve the problem of insufficient blood supply to the femoral head. It is difficult for the metal tantalum rod to achieve satisfactory bone healing at the lesion site. Necrosis and implant bone resorption may also occur, which will lead to a second collapse.

[0004] Artificial biological scaffolds should have a macroscopic / microscopic structure similar to that of natural organs, providing space and an environment for the growth of various human cells and tissues, and can also serve as carriers of growth factors. Studies have shown that in many cases, if bone implants can appropriately load stress to the surrounding tissues after surgery, it can improve and promote the growth and healing of the surrounding bone tissue. Existing support implants are unable to provide internal stress to the surrounding tissues, which is not conducive to postoperative healing. In short, the key problem of currently developed biological implants is their single structure, which makes it difficult to match the biological and mechanical properties of complex human organs. The force incompatibility between the implant and the bone tissue may lead to insufficient stimulation of the surrounding bone tissue, which may cause the bone tissue to be reabsorbed by the body over an extended period of time after implantation, leading to bone acidification or fracture. Over time, for example, it can induce "stress shielding", inflammation, cell apoptosis and human tissue damage.

[0005] Bone implants should be able to restore or improve microcirculation at the implant site. However, existing implants designed to restore or improve microcirculation in vascular implants suffer from complex structural molding and assembly, making vascular implantation inconvenient during surgery. From a production perspective, these products suffer from cumbersome processes, high costs, uncontrollable process flows, and poor economic viability. Furthermore, they face operational difficulties and suboptimal implant integration during surgery.

[0006] Therefore, there is a need for a bone implant that generates internal stress to promote bone integration, provides microcirculation reconstruction, and can be partially or completely degraded after implantation to increase bone mass, with controllable production costs and good practical effects. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an implantable device that can continuously apply internal stress to promote bone integration, self-adaptive retention, and microcirculation reconstruction, and has an easy-to-process structure and simple surgical operation.

[0008] A microcirculation reconstruction bone implant that generates internal stress includes a stent shell and a stent core; the stent shell is sleeved on the outside of the stent core and forms a matching structure with the stent core; the stent shell is located between the bone tissue and the stent core, and when implanted and loaded, the stent shell undergoes elastic deformation to generate internal stress and apply it to the surrounding bone tissue; the stent core also carries a microcirculation reconstruction pathway.

[0009] Furthermore, an opening is formed at the rear end of the bracket shell, and the bracket core is inserted into the bracket shell through the opening.

[0010] Furthermore, the stent shell is cup-shaped and forms a longitudinally extending inner cavity, having a generally cylindrical or conical wall, which defines the inner cavity; the stent core cooperates with the inner cavity of the stent shell and can be generally cylindrical or conical.

[0011] Furthermore, the implant also includes a base, the inner core of the stent is installed at the head end of the base, and the tail end of the stent shell is connected to the head end of the base.

[0012] Furthermore, the tail end face of the stent core is provided with a positioning recess, and the head end face of the base is provided with a positioning protrusion. The positioning recess and the positioning protrusion are inserted along the length direction of the implant and are positioned and matched to prevent relative rotation between the stent core and the base.

[0013] Furthermore, a connecting seat is provided at the head end of the base, a first external thread is formed on the outer periphery of the connecting seat, and an internal thread is formed at the tail end opening of the bracket shell, and the bracket shell and the base are connected through the internal and external threads.

[0014] Furthermore, a second external thread is formed at the tail end of the inner core of the bracket. After the inner core of the bracket is positioned and matched with the head end of the base, the first external thread and the second external thread form an integral matching thread, which is threadedly connected to the inner thread of the bracket shell.

[0015] Furthermore, the inner core of the stent provides a microcirculation reconstruction structure. A sink groove is arranged axially on the outer side of the inner core of the stent. The sink groove is used for implanting blood vessels. The sink groove is opened on opposite sides of the inner core of the stent. A U-shaped through groove is provided at the head end of the inner core of the stent. The U-shaped through groove connects the sink grooves on both sides of the inner core of the stent.

[0016] Furthermore, a locking spring is provided on the outer periphery of the connecting seat, and a locking recess is provided on the inner wall of the opening at the rear end of the bracket shell. The locking spring cooperates with the locking recess to perform positioning and locking.

[0017] Furthermore, the inner core of the stent is made entirely or partially of degradable materials, or entirely of non-degradable materials.

[0018] The beneficial effects of the present invention are: the stent inner core and the stent outer shell are matched in a manner that they are initially separated and then combined during application, which facilitates the intraoperative vascular implantation operation; the elastic effect formed by the coordination between the stent inner core and the stent outer shell can maintain the stability of the implant during initial implantation, and can continuously apply internal stress to the bone tissue during postoperative application to promote bone growth and integration; the application of the new implant can establish a new bone circulation, stabilize the fixation, adapt to the internal stress of the femoral head, provide blood circulation and a stress environment for bone growth, and promote the postoperative healing effect after the implant is applied. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the bracket assembly structure;

[0020] Figure 2 Schematic diagram of the spatial position of each component of the bracket Figure 1 ;

[0021] Figure 3 Schematic diagram of the spatial position of each component of the bracket Figure 2 ;

[0022] Figure 4 Schematic diagram of the bracket shell structure;

[0023] Figure 5-6 Schematic diagram of the stent core structure;

[0024] Figure 7-8 Schematic diagram of the base structure;

[0025] Figure 9-10 Schematic diagram of the cross-section of the stent assembly structure (excluding the implanted blood vessel);

[0026] Figure 11-12 Schematic diagram of the cross-section of the stent assembly structure (including the implanted blood vessel);

[0027] Reference numerals in the figure: 1 stent shell; 11 porous portion; 12 connecting portion; 121 locking recess; 2 base; 21 blood vessel channel; 22 positioning protrusion; 23 central channel; 24 connecting seat; 241 locking spring; 3 stent inner core; 31 sinking groove; 32 positioning recess; 33 central hole; 34 U-shaped through groove; 4 implanted blood vessel. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] refer to Figure 1-3, a schematic diagram of a stent assembly structure is shown; the stent includes: a stent shell and a stent core, the stent core being insertable into and coupled to the stent shell. The stent, as a support implant, can be provided for insertion into a surgical site (such as a hole in a bone), and in the specific example herein, into the femoral head.

[0030] The stent is a press-fit implant and preferentially forgoes the use of threads as the primary mechanism for bone engagement. This allows the support implant to be placed at the desired depth in the bone using only longitudinal driving force, without the need for rotational insertion, while still providing sufficient initial stability. It should be noted that when the implant is placed in the bone, the deeper position is the head end, while the shallower position is the tail end. That is, the stent shell 1 is located at the head end of the stent, and accordingly, the stent core 3 is also located at the head end of the stent.

[0031] like Figure 9 、 10 As shown, the bracket shell 1 includes a porous portion 11 at the head end and a connecting portion 12 at the tail end. The porous portion 11 can be a porous material with overall gaps connected made of 3D metal printing. The connecting portion 12 is set at the tail end of the porous portion 11. The connecting portion 12 is made of solid material and is processed with internal or external threads.

[0032] like Figure 4 As shown, the connecting portion is further processed with a locking recess 121 that cooperates with the locking spring 241 .

[0033] like Figure 7-8 As shown, the bracket further includes a base 2 at the tail end, the base 2 is a solid material, and the head end of the base 2 has a connecting seat 24. The surface of the connecting seat 24 is provided with a thread, and the connecting portion 12 is connected to the connecting seat 24 by means of a thread. The head end surface of the connecting seat is also provided with a positioning protrusion 22, which is a protruding structure on the head end surface of the connecting seat. It can be columnar, such as a square column, a cylindrical column or a conical column as needed. There can be one or more positioning protrusions 22 as needed, and their shape can be reasonably selected as needed. The positioning protrusion 22 is used to cooperate with the positioning recess 32 on the inner core of the bracket, so that the inner core 3 of the bracket is positioned and installed on the head end of the base 2 in an insert-fit manner.

[0034] The outer peripheral surface of the connecting seat 24 also has a locking spring 241, which cooperates with the locking recess 121 of the connecting portion of the bracket shell 1 to provide a positioning locking function when the bracket shell 1 and the base 2 are threadedly connected.

[0035] like Figure 1As shown, the outer surface of the base 2 may be provided with a roughened surface or threads to increase friction with the bone during implantation, thereby facilitating stronger attachment of the stent body to the bone. Furthermore, in this application, since the expandable structure of the stent shell at the head end of the base 2 inherently provides retention, the roughened surface or threads at the base can be designed to be less stressful, such as with thinner and shorter threads. It is also preferable to forgo threads as the primary mechanism for bone engagement, and to use a roughened surface instead.

[0036] The base has a pair of blood vessel channels 21. When the stent core 3 is connected to the base connector, the blood vessel channels 21 are used to pass the implanted blood vessel 4. The bottom surface of the base 2 is designed with a concave hole or groove for connecting with external instruments for surgical operation.

[0037] The rear end of the stent shell 1 forms an opening, through which the stent core 3 is inserted into the stent shell 1. The stent shell 1 (porous member) is cup-shaped and forms a longitudinally extending inner cavity. The stent shell 1 (porous member) has a generally cylindrical or conical wall, which defines its inner cavity. To facilitate radial expansion, the wall should not be too thick, having a thickness of approximately 1-2 mm. The stent core 3 has an outer shape that matches the inner cavity.

[0038] The head end of support mainly comprises the support core 3 (rigid component) with relative rigidity and the support shell 1 (porous component) that at least part of porous material has relative elasticity. Support core 3 (rigid component) is positioned in the inside of support shell 1 (porous component). When support is placed in the hole in the bone, support shell 1 (porous component) is engaged to the peripheral surface of support core (rigid component). Utilize this structure, when the patient is active after surgery, the longitudinal force transmitted by the support peripheral tissue cancellous bone body can be applied to the support core (rigid component) by support shell 1, and support core 3 (rigid component) further supports and squeezes support shell 1 (porous component). This active force makes support shell 1 (porous component) expand radially outwards in the surrounding bone of surgical site, and this expansion takes effect and can make support settle and retain well.

[0039] The relatively elastic nature of the porous material enables the stent shell 1 to expand, anchoring it to the surrounding bone. To allow the implant's porous material to expand, the elastic modulus of the expanding portion of the stent shell 1 (porous component) should be approximately 3 GPa or less. When the implant's porous material expands radially, the porous material cuts into the bone. The outer surface of the porous material can be formed with metal trabeculae or sharp protrusions extending from the outer surface. When the trabeculae are pressed against the bone surface, they cut into the bone. To provide this cutting action when the implant's stent shell 1 (porous component) expands, the compressive strength of the porous material should be approximately 50 MPa to approximately 90 MPa, which is relatively higher than the compressive strength of cancellous bone, which is approximately 10 MPa to approximately 50 MPa. The contact area between each trabecula and the bone is very small. When moderate loads are applied, high stresses will be generated. Because the porous material is stronger than the surrounding bone tissue, the porous material will cut into the bone.

[0040] Because bone tissue is pressed into the pores of porous material, bone tissue can be promoted to be integrated into the implant and enter the pores of porous material. When the support shell 1 (porous component) structural grid cuts into the bone, it causes bone bleeding at the same time, stimulating bone growth by promoting the production of beneficial cells (such as osteoblasts and osteoclasts). The bone fragments that fall into the pores on the porous material also contribute to bone reconstruction. During bone reconstruction, osteoblasts use bone fragments as scaffolds and produce new bone material around the bone fragments. At the same time, osteoclasts remove bone fragments by reabsorbing and decomposing bone, and release minerals (such as calcium) from the bone fragments and return them to the bloodstream. Osteoblasts will replace the ground bone fragments from the hole and the implant device with new healthy bone in and around the removal site (implant hole). The composite composed of new healthy bone and porous material that is grown internally has elastic properties that are closer to bone than a single solid metal implant, thereby helping to maintain the actual load condition of the bone near the implant.

[0041] like Figure 5 、 Figure 6 As shown, the stent core 3 (rigid member) cooperates with the inner cavity of the stent shell 1 and can be generally cylindrical or conical. The outer surface of the stent core 3 can be smooth, but can be roughened or otherwise treated to promote bone growth or limit bacterial growth.

[0042] In other embodiments, there is a certain dimensional tolerance between the stent core 3 and the inner cavity of the stent shell 1. That is, the outer diameter D of the outer surface of the stent core 3 can be slightly larger than the inner diameter d of the inner cavity of the stent shell 1. The ratio of the outer diameter D to the inner diameter d can be selected and applied as needed. The outer diameter D / inner diameter d is usually selected as 1.01-1.05, and the ratio can be increased in steps of 0.01. In the application, the same stent shell can be configured with different models of stent cores, which can be selected as needed to achieve different outer diameter D / inner diameter d ratios. The internal stent core is used to support the elastic stent shell 1 to form an internal stress retention structure at the stent head end. The selection of different outer diameter D / inner diameter d ratios can determine the range of the stress within the stent. In specific applications, it is selected according to the patient's individualized data to achieve the adaptation of the stress within the stent to the patient.

[0043] Different patients have different bone tissue parameters due to factors such as age, physical condition, and work. The pressure exerted on the surrounding bone tissue by the internal stress of the scaffold will promote the recovery and growth of bone tissue under the pressure stimulation of the internal stress. Therefore, different internal stress effects need to be provided to different patients. Through personalized adaptation, optimized post-implantation treatment effects can be achieved for different patients.

[0044] When there is no need to selectively adjust the internal stress of the stent, the outer diameter D of the outer surface of the stent core 3 can also be equal to or slightly smaller than the inner diameter d of the inner cavity of the stent shell 1, that is, the stent core does not need to participate in the adjustment of the internal stress. When implanted in the bone, the drilling holes on the bone cause the stent shell to be deformed by squeezing, and the mechanical properties of the stent shell are used to maintain its external stress effect.

[0045] The stent core 3 is configured to cause the porous portion 11 to expand when inserted into the lumen of the stent shell 1. Since the elastic modulus of the porous member is significantly lower than that of the rigid member, when the rigid member enters the lumen, the porous member will expand radially outward and abut against the bone tissue in the pores.

[0046] In practice, the stent core 3 can be solid or porous. The elastic modulus of the stent core and the stent shell can be adjusted as needed to form different overall stent characteristics: the elastic modulus is consistent inside and outside, the elastic modulus inside is greater than the outside, or the elastic modulus outside is greater than the inside.

[0047] In one embodiment, the stent core 3 (rigid component) is formed of a relatively strong hard metal (such as titanium) or bioceramic.

[0048] In addition, the stent core can also be made of a degradable material, such as a zinc alloy, which can provide internal strength support. After implantation, the stent shell's internal structure and surface stress uniformity can be ensured in the initial implantation period, allowing it to better withstand and transmit the body's pressure from the bone tissue. As new bone tissue grows, it will penetrate the porous structure of the stent shell 1 and enter the inner cavity. As the new bone grows, the degradable material of the stent core 3 is absorbed and replaced, while continuing to maintain the strength and stability of the stent shell. Ultimately, the degradable material of the stent core implanted in the body can be degraded and absorbed, increasing bone mass and further promoting the growth of bone tissue and vascular tissue into the inner cavity of the stent shell.

[0049] In other embodiments, the stent core 3 may also be a porous structure. If a porous structure is used, it can be a porous structure with interconnected pores made by 3D printing. In addition, when the stent core 3 adopts a porous structure, since the outer surface of the porous structure has pores and the stent core is used to support and withstand the human body pressure from the bone tissue, in order to provide additional initial mechanical strength and stability to the porous structure of the stent core, the porous structure of the stent core can be pre-infiltrated with a filler material. The filler material also uses a resorbable metal material or polymer material. Examples of resorbable polymers include polylactic acid (PLA), polyglycolic acid (PGA), polylactic-co-glycolic acid (PLGA), polyhydroxybutyrate (PHB), polyhydroxyvalerate (PHV) and their copolymers, polycaprolactone, polyanhydride, and polyorthoester. The resorbable material filled in the porous structure of the stent core can ensure uniform force on the internal structure and surface of the stent core during the initial implantation, better withstand and transmit the human body pressure from the bone tissue, and as the filler material is absorbed and replaced as new bone grows, the strength and stability of the implant structure are also maintained. Various degradable materials can be degraded and absorbed after being implanted into the body, promoting the growth of bone tissue and vascular tissue into the stent core.

[0050] In another embodiment, the stent core can be designed to form a simple frame structure, such as a grid-like, multi-sheet, or multi-layered space frame. The frame structure is used to pre-fill a filling material, and the filling material is a resorbable metal material or polymer material. By changing and adjusting the shape and material of the frame structure, and coordinating the pre-filled filling material, the mechanical structural characteristics of the stent core can be adaptively adjusted. Before surgery, bone tissue force analysis modeling can be performed based on the patient's bone quality and physical condition, and a frame force structure suitable for individual parameters can be generated. The frame is formed by processing using technologies such as 3D printing, and the stent core for individual applications is formed by pre-filling the filling material.

[0051] The rigid stent core can be used to support the elastic stent shell 1 to form an internal stress retention structure of the stent. When implanted in bone tissue, the internal rigid stent core can continuously drive the stent shell 1 to apply force to the surrounding bone tissue due to the force and support effect. Under the continuous application of internal stress, it can stimulate the surrounding bone tissue to grow, integrate and recover well.

[0052] The inner core of the stent also provides a microcirculation reconstruction structure. A semicircular or rectangular groove 31 is axially provided on the outer side of the inner core of the stent. The side of the groove 31 is open to the side wall of the inner core of the stent. The width of the opening is convenient for inserting blood vessels from the side, thereby improving the convenience of intraoperative operation. By transplanting blood vessels (such as large / small saphenous veins, small arteriovenous bundles in adjacent or other parts, artificial blood vessels, or artificial blood vessels combined with autologous blood vessels, etc.) into the groove 31 of the stent and extending it through the inner core of the stent, the blood vessels can be implanted into the stent. The number and position of the grooves 31 can be set on the inner core of the stent as needed. Usually, the grooves 31 are opened on opposite sides of the inner core of the stent, with one on each side.

[0053] The stent core has a smooth U-shaped through-groove 34 at the head end, connecting the two side grooves 31. The opening width of the through-groove 34 facilitates the insertion of a blood vessel from the side, meaning that the vessel can be placed directly into the grooves 31 and 34 from the side. Inserting a blood vessel from the side is simpler than conventional insertion. The implanted blood vessel can smoothly fold back from one side groove 31 of the stent core through the U-shaped through-groove 34 to the other side groove 31. The two side grooves 31 form a smooth concave surface where they meet the ends of the U-shaped through-groove 34, ensuring that the blood vessel does not protrude from the surface of the stent core when folding back or passing through, thus protecting the vessel.

[0054] The implanted blood vessel is placed in the groove 31 of the stent core, and the implanted blood vessel also passes through the base 2 of the stent. The groove 31 is formed with an opening on the tail end face of the stent core. When the stent core is connected to the connecting seat of the base, its opening is connected with the blood vessel channel 21 on the base. The stent core needs to maintain a fixed angle relative to the base to prevent the two from rotating and damaging the internal implanted blood vessel. A positioning recess 32 is also formed on the tail end face of the stent core. The positioning protrusion 22 on the connecting seat is used to cooperate with the positioning recess 32 on the stent core, so that the stent core is positioned and installed on the head end of the base 2 in an insert-fit manner. By using the positioning protrusion 22 and the positioning recess 32 to cooperate with each other, the stent core remains fixed relative to the base, thereby ensuring the safety of the implanted blood vessel 4 that passes through the stent core and the base.

[0055] A center hole 33 is also added at the center of the stent core, which runs through the entire length and forms a channel between the rear end face of the stent core and the U-shaped through groove 34. A center channel 23 is also set in the center of the base 2 of the stent, and the center channel 23 runs through the base 2. When the stent core is installed on the connecting seat of the base, the center channel 23 and the center hole 33 of the stent core form a coaxial through structure, together forming a complete center channel. The center channel of the stent core can be used as a pressure relief hole, a drug sustained release chamber, etc. The center channel can be used as a channel for targeted drug implantation; by placing magnetic components, it can be used as a magnetic target for the action of an external magnetic field; it can be used as an endoscopic detection channel; it can be used as a phototherapy, acupuncture channel, etc. In addition, the center channel of the stent core can be used to discharge metabolic waste generated during bone growth or introduce drugs.

[0056] The stent core 3 and stent outer shell 1 need to be mounted and fixed to the connecting base 2. A first external thread is formed on the outer periphery of the connecting base 24, while a second external thread is also formed on the outer periphery of the rear end of the stent core 3. After the positioning recess 32 on the stent core mates with the positioning protrusion 22 on the connecting base, the first and second external threads form a single, integrated mating thread. This mating thread mates with the internal thread of the connecting portion 12 at the rear end of the stent outer shell 1, connecting the base 2 and stent core 3 integrally.

[0057] In an optimized embodiment, the outer surface of the connection base 24 also includes a locking spring 241. This spring 241 engages with the locking recess 121 of the connection portion of the bracket housing 1, providing a locking position when the bracket housing 1 and base 2 are threaded together. The base 2 connection base 24 is provided with a receiving cavity around its periphery for receiving the locking spring 241. These cavities cooperate with the locking recess 121 of the connection portion. Preferably, two cavities are provided, arranged symmetrically. The locking spring 241 comprises a cylindrical body with an inner elastic body and a hemispherical projection at the head. Under external pressure, the hemispherical projection compresses the inner elastic body. The locking spring is placed within the cavity. When the bracket housing 1 and base 2 connection base are threaded together, once the bracket housing is rotated to a predetermined position, the hemispherical projection springs into the locking recess 121 of the bracket housing connection, providing a locking and securing action, thus securing the threaded connection between the bracket housing and base.

[0058] In order to place the implant in the hole in the bone, the stent core 3 and stent shell 1 are initially separated from each other. First, the physician arranges the implanted blood vessel 4, connects the two ends of the implanted blood vessel 4 with a guide wire, and places it along the groove 31 on one side of the stent core 3, then bypasses the U-shaped groove 34 at the head end and places it in the groove 31 on the other side. After the operation is completed, the implanted blood vessel passes through the U-shaped groove 34 and spans the grooves 31 on both sides of the stent core. The stent core with the implanted blood vessel is positioned on the base, and after connecting the two ends of the implanted blood vessel with a guide wire, it passes through the vascular channel 21 in the base 2 and extends out. The stent shell 1 is inserted into the stent core 3, and the stent shell 1, stent core 3, and base 2 are fixedly connected by threaded connection to form an integrated implant. After assembly, the implant is inserted into the hole in the bone. Once inserted, the physician uses an osteotome to engage the base 2 of the stent to generate longitudinal force and press or knock the assembled implant into the hole. As mentioned above, the bracket shell will first contact the bone tissue. Under the pressure of the external bone tissue and the support of the internal bracket core, the bracket shell will generate an elastic force on the external bone tissue. The porous component of the bracket shell 1 cuts into the surrounding bone tissue that defines the hole, and the porous component presses against the surrounding bone that forms the hole.

[0059] After passing through the vascular channel 21 in the base 2, the transplanted blood vessels implanted in the sink 31 can anastomose with the existing blood supply system around the hip joint (such as the lateral femoral circumflex artery and vein system), achieving vascularization of the stent. This promotes blood vessel growth within the stent and the affected area, reconstructing the microcirculatory system in the affected area, providing the necessary stem cells, oxygen, nutrients, and growth factors for the new bone tissue, and removing local metabolic waste. The stent can be used directly after implantation in the vascular bundle. Growth factors (such as BMP-2 / VEGF) or stem cells can also be loaded into the porous structure of the stent shell and stent core to further enhance its ability to promote bone regeneration.

[0060] Figure 11 、 12 The cross-sectional view of the assembled stent is shown. After assembly, the stent can be implanted in the cavity formed after the removal of the femoral head avascular necrosis core decompression lesion, playing a role in biomechanical support and promoting the growth of blood vessels and bone tissue. The stent shell 1 and the stent core 3 can be prepared by 3D printing technology, and can also be prepared by non-3D printing technology (such as vapor deposition or sintering, etc.). The stent can be processed into other arbitrary shapes as needed. The stent is a porous titanium alloy stent, and the material of the stent can also be tantalum, titanium-tantalum alloy, nickel-titanium alloy, pure titanium, cobalt alloy, calcium phosphate, hydroxyapatite, polylactic acid (PLA), lactic acid-glycolic acid copolymer (PLGA), polyacetic acid lactone (PCL), coral or bioceramics and other materials.

[0061] In addition to 3D printing, the press-fit implants can also be conventionally machined or cut using electrical discharge machining (EDM). They can also be manufactured using vapor deposition, mesh manufacturing processes, ceramic 3D printing processes, and conventional machining processes.

[0062] Finally, it should be noted that the foregoing description is merely an explanation of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail, those skilled in the art will be able to modify the aforementioned technical solutions or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A microcirculation reconstruction bone implant that generates internal stress, comprising a stent shell and a stent core; characterized in that: The stent shell is placed on the outside of the stent core and forms a matching structure with the stent core; the stent shell is located between the bone tissue and the stent core. When implanted and loaded, the stent shell undergoes elastic deformation to generate internal stress and apply it to the surrounding bone tissue; the stent core also carries a microcirculation reconstruction pathway.

2. The microcirculation reconstruction bone implant generating internal stress according to claim 1, characterized in that: An opening is formed at the rear end of the bracket shell, and the bracket core is inserted into the bracket shell through the opening.

3. The microcirculation reconstruction bone implant generating internal stress according to claim 2, characterized in that: The stent shell is cup-shaped and forms a longitudinally extending inner cavity, with a generally cylindrical or conical wall defining the inner cavity; the stent core cooperates with the inner cavity of the stent shell and can be generally cylindrical or conical.

4. The microcirculation reconstruction bone implant generating internal stress according to claim 2, characterized in that: The implant also includes a base, the inner core of the stent is installed at the head end of the base, and the tail end of the stent shell is connected to the head end of the base.

5. The microcirculation reconstruction bone implant generating internal stress according to claim 4, characterized in that: The tail end face of the stent core is provided with a positioning recess, and the head end face of the base is provided with a positioning protrusion. The positioning recess and the positioning protrusion are inserted along the length direction of the implant and are positioned and matched to prevent relative rotation between the stent core and the base.

6. The microcirculation reconstruction bone implant generating internal stress according to claim 5, characterized in that: A connecting seat is provided at the head end of the base, a first external thread is formed on the outer periphery of the connecting seat, and an internal thread is formed at the tail end opening of the bracket shell, and the bracket shell and the base are connected through the internal and external threads.

7. The microcirculation reconstruction bone implant generating internal stress according to claim 6, characterized in that: The tail end of the bracket inner core forms a second external thread. After the bracket inner core is positioned and matched with the head end of the base, the first external thread and the second external thread form an integral matching thread, which forms a threaded connection with the internal thread of the bracket shell.

8. The microcirculation reconstruction bone implant generating internal stress according to claim 1, characterized in that: The inner core of the stent provides a microcirculation reconstruction structure. A sink groove is arranged axially on the outside of the inner core of the stent. The sink groove is used for implantation into blood vessels. The sink groove is opened on opposite sides of the inner core of the stent. There is a U-shaped through groove at the head end of the inner core of the stent, and the U-shaped through groove connects the sink grooves on both sides of the inner core of the stent.

9. The microcirculation reconstruction bone implant generating internal stress according to claim 6, characterized in that: A locking spring is provided on the periphery of the connecting seat, and a locking recess is provided on the inner wall of the opening at the rear end of the bracket shell. The locking spring cooperates with the locking recess to perform positioning and locking.

10. The microcirculation reconstruction bone implant generating internal stress according to claim 6, characterized in that: The inner core of the stent is made entirely or partially of degradable materials, or entirely of non-degradable materials.

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